Field
The present disclosure relates to adjustable rolls such as can be used on grinding equipment and more particularly pertains to a new roll adjustment system for detecting the zero point for a movable roll more safely and accurately.
Description of the Prior Art
In machinery utilizing rolls or rollers (the terms being used interchangeably in this description), such as grain processing apparatus, the rolls typically have teeth formed on the substantially cylindrical outer surface to grind or substantially pulverize the grain particles passing between a pair of the rolls, or multiple pairs of rolls arranged in series with respect to each other. The separation gap between the pair of rolls is very important to achieving a ground product that has the desired particle size and consistency. However, the separation gap needs to be changed or adjusted from time to time due to, for example, a desired change in the character of the output product, loss of the proper position adjustment of the rolls, wear on the parts of the apparatus (e.g., the teeth on the rolls), as well as other reasons.
For example, during startup of the grinding apparatus, the roll separation gap is typically adjusted to a suitable or desired setting. To do so, a proper zero location or point for the movable roll must be determined from which the separation gap may be measured. The zero location may be defined as the position of the movable roll in which the movable and stationary rolls are in contact with each other, or at least the ends of the rolls are in contact with each other, such that the rotation axes of the rolls are presumed to be substantially parallel.
The zero location is thus determined by detecting when the rolls just contact each other to establish a zero point. Then adjustment of the separation gap may be made between the rolls based upon the zero point. In some apparatus, the separation gap between the rolls may be adjusted by moving the position of the bearings supporting the ends of the movable roll. Each of these bearings may include a spring-loaded mount in which a threaded bolt or rod is used to adjust the position of the bearing of the movable roll with respect to the other (stationary) roll. Rotation of the bolt or rod moves the bearing, and the corresponding end of the movable roll, closer to or further away from the stationary roll depending upon the direction of rotation of the bolt or rod.
The process of adjusting the separation gap between the rolls may initially entail operating the apparatus so that the rolls rotate in a spaced relationship of (usually) unknown separation gap, and then moving the rotating movable roll relatively closer to the rotating stationary roll until contact is detected between the movable and stationary rolls. The point at which contact is detected is considered to be the zero point for the movable roll.
Accurately detecting the initial point of contact between the rotating rolls can be difficult. One way of detecting contact (or imminent contact) requires the insertion of a feeler gauge between the movable and stationary rolls, and when a feeler gauge can no longer be inserted between the rolls, contact between the rolls is detected and the zero point is identified. Another way of detecting contact requires the operator to listen for the sound produced by the initial contact of the rotating rolls as the moving roll moves toward the stationary roll, to thereby identify the zero point.